Eyeworld

18 December 2018 EW NEWS & OPINION by Maxine Lipner EyeWorld Senior Contributing Writer Research highlight ries of 37 patients with chronic ND. Investigators looked at how effective such treatments were for alleviating negative dysphotopsia. For the 22 patients who un- derwent reverse optic capture as a secondary procedure, investigators determined that this was almost always successful. "We've had suc- cess in all but one case," Dr. Masket said, adding that in 21 primary cases they've been 100% successful. The investigators, including Dr. Masket's partner, Nicole Fram, MD, also evaluated which IOLs were involved in cases of negative dys- photopsia and found that virtually all IOLs could be associated with this. They determined that in their series, 23% of IOLs were silicone and 12.8% of these had round edges. "I hope that we have been successful in dispelling the myth porating capsulorhexis into their surgeries. "Prior to that we used can-opener capsulotomies," he said, adding that with this early approach the majority of lenses ended up with one loop in and one loop out of the bag. "We started to look at the rela- tionship of the anterior capsulotomy to the anterior surface of the IOL as being one potential site for induc- tion of negative dysphotopsia." Dr. Masket decided that he would try a new approach by plac- ing the optic in front of the capsule, rather than behind the capsule while leaving the loops in the bag for support. "That strategy worked extremely well," he said. Studying treatments That method, as well as other approaches, were considered in the recent consecutive surgical case se- With the assumption of a particular lens style being responsi- ble, many practitioners, including Dr. Masket, exchanged (bag to bag) such acrylic IOLs for round, silicone IOLs with a low index of refrac- tion for symptomatic patients. "In our experience, we had no success with this strategy," Dr. Masket said. Meanwhile, an investigation 2 done by Peter Vamosi, MD, helped to enhance Dr. Masket's understand- ing. Dr. Vamosi reported that if he exchanged the lens in the bag for one made of a different lens mate- rial, he had no success. However, if he exchanged the in the bag lens for one in the sulcus, he was successful. In his study, position of the IOL was paramount, not the material or the design. Another theory was based on the expanded space between the back of the iris and the front of the lens implant (posterior chamber) in the pseudophakic eye. Surgeons filled this gap with a piggyback IOL, with moderate success. "It's about 70% successful," Dr. Masket said. However, in a case where he attempted to shallow the posterior chamber by fixating the lens bag to the iris, he found that this failed to help. In addition, the Vamosi study indicated that the depth of the pos- terior chamber was identical in both the symptomatic patient group and the controls, disproving the theory that the expanded posterior cham- ber was causal for ND. Dr. Masket noted that during the late 1980s surgeons not only changed the lenses they were implanting but also began incor- F or patients with complaints of negative dysphotopsia (ND), a surgical strategy of secondary reverse (anterior) optic capture can remedy the situation, according to Sam- uel Masket, MD, Los Angeles. Dr. Masket reported on study results 1 in remedying negative dysphotopsia in the Journal of Cataract and Refrac- tive Surgery. In all but one case of secondary reverse optic capture, this technique was successful. In cases of negative dysphotop- sia, the typical complaint centers around a dark temporal crescent or line in the periphery of patients' vision. One of the ironies with the condition is its association with a well-centered posterior chamber lens in the capsule bag with an over- lapping anterior capsulotomy for 360 degrees. "We only see it under what we consider to be anatomically perfect postoperative circumstanc- es," Dr. Masket said, adding that if there's significant decentration, significant tilt from capsule damage, ND tends not to occur. Shifting theories Theories on the condition have abounded over the years. "Negative dysphotopsia was first reported in 2000 by Jim Davison, MD," Dr. Masket said. "It corresponded to the same time that acrylic IOLs became popular in the market." The assump- tion was that the chief cause of ND was the single- or multi-piece acrylic IOL with a high index of refraction and a square edge; these character- istics were already associated with positive dysphotopsia (PD). Surgical remedy for negative dysphotopsia Secondary reverse optic capture in a symptomatic patient Source: Samuel Masket, MD Cataract study on mortality retracted and replaced I n June 2018, EyeWorld ran a "Research highlight" titled "New ben- efit of cataract surgery" about a JAMA Ophthalmology article pub- lished online in October 2017 and in print in January 2018. The article examined the impact cataract surgery could have on an older patient's mortality, and the EyeWorld piece summarized the findings and interviewed one of the study authors. At the time, the study 1 investigators said that undergoing cataract surgery could lower the risk of death from all causes for patients age 65 and older. However, this conclusion was subsequently found to be erroneous. In August 2018 online and in November 2018 in print, the authors withdrew the original article and replaced the study with a revised version that concluded the opposite: Older individuals who underwent cataract surgery were actually at increased risk of mortality. An issue with one of the variables used in the study prompted the retraction and replacement. In the retraction notice, 2 the authors explained that after being contacted by a reader who questioned the time-varying model used in the study, they reexamined the data. They realized that they had mistakenly defined the time-to-event variable as the period since undergoing cataract surgery, rather than using the diagnosis date as the starting point. The investigators determined that their original conclusion was, for the most part, no longer valid. The only exception was mortality related to neurologi- cal issues, which was still lower in those over 65 who underwent the cataract procedure. EyeWorld would like to alert readers of this new conclusion, which turned out to be very different from the original. We want to ensure readers remain apprised of these latest findings and what they could mean for older patients considering cataract surgery. EW References 1. Tseng VL, et al. Association of cataract surgery with mortality in older women: findings from the Women's Health Initiative. JAMA Ophthalmol. 2018;136:3–10. 2. Tseng VL, et al. Notice of retraction and replacement. Tseng et al. Association of cata- ract surgery with mortality in older women: findings from the Women's Health Initiative. JAMA Ophthalmol. 2018;136:1313–1314.

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